Wachsman J T, Hogg L
J Bacteriol. 1964 May;87(5):1118-22. doi: 10.1128/jb.87.5.1118-1122.1964.
Wachsman, J. T. (University of Illinois, Urbana), and L. Hogg. Use of thymineless death to enrich for doubly auxotrophic mutants of Bacillus megaterium. J. Bacteriol. 87:1118-1122. 1964.-When strain KM:T(-), a thymine auxotroph of Bacillus megaterium strain KM, is allowed to undergo thymineless death on a minimal medium, the survivors are greatly enriched in polyauxotrophic mutants. Cells were irradiated with ultraviolet light, grown in the presence of thymidine and a complete amino acid mixture, and then starved for thymidine in the absence of amino acids. Doubly auxotrophic mutants (thymine(-) amino acid(-)) may account for more than 90% of the survivors. The most reproducible results were obtained when sucrose (0.4 m) was added to both growth and starvation media. Although the percentage of mutants among the survivors increases with the time of thymine starvation, the absolute number of double auxotrophs per milliliter decreases. It is probable that the extent of cross-feeding determines both the mutant yield and the mutants types. Substrains of KM:T(-) having additional requirements for each of the following amino acids have been isolated: histidine, threonine, tyrosine, tryptophan, arginine, isoleucine, methionine, serine, and cysteine.
瓦克斯曼，J.T.（伊利诺伊大学厄巴纳分校）和L.霍格。利用无胸腺死亡法富集巨大芽孢杆菌的双营养缺陷型突变体。《细菌学杂志》87:1118 - 1122。1964年。 - 当巨大芽孢杆菌KM株的胸腺嘧啶营养缺陷型菌株KM:T(-)在基本培养基上经历无胸腺死亡时，存活者中多营养缺陷型突变体大量富集。细胞先用紫外线照射，在胸腺嘧啶核苷和完整氨基酸混合物存在的情况下生长，然后在无氨基酸的情况下使其缺乏胸腺嘧啶核苷。双营养缺陷型突变体（胸腺嘧啶(-)氨基酸(-)）可能占存活者的90%以上。当在生长培养基和饥饿培养基中都添加蔗糖（0.4 m）时，可获得最可重复的结果。尽管存活者中突变体的百分比随胸腺嘧啶饥饿时间增加，但每毫升双营养缺陷型的绝对数量减少。交叉营养的程度可能决定了突变体产量和突变体类型。已经分离出对以下每种氨基酸有额外需求的KM:T(-)亚菌株：组氨酸、苏氨酸、酪氨酸、色氨酸、精氨酸、异亮氨酸、蛋氨酸、丝氨酸和半胱氨酸。
